Pipeline and vessel structures used in the oil and gas industry are exposed to stresses over time that can accumulate to produce defects in the structure. Unfortunately, it is typically difficult to determine whether such structures are being subjected to damaging stresses until easily observable defects occur.
The availability of non-destructive inspection techniques for structural materials, for instance, nonmetallic pipes used in pipelines, is limited. For the most part, the techniques available so far are either destructive to the material or are experimental and unreliable. Even considering current experimental techniques for non-destructive inspection, no current techniques are able to reliably predict the formation of defects, and are generally used to detect only existing defects.
More specifically, existing building materials and the corresponding systems and techniques for inspection of the materials are inadequate for detecting the presence of stresses on or in the material such as tensile stress or compressive stress with sufficient accuracy and precision such that defects can be predicted before they occur. Currently available technologies for sensing material defects are generally based on mono-dimensional fiber Bragg gratings. These fibers provide mono-dimensional information: i.e., they can detect only stress that occurs along the length of the fiber, and only substantial stresses that correspond to already damaged materials with significant cracks and ruptures in the structural material.
There is a need for systems and methods for detecting perturbations in structural materials that utilize a photonic material, such as an optical grating or a photonic crystal, as a sensitive element for diffraction generation. In addition, there is a need for systems and methods for detecting perturbations in structural materials that quantify deformations in photonic materials through a wavelength change, or a diffraction angle change quantified from an intensity variation. Moreover, there is a need for systems and methods for detecting perturbations with a sensitivity that is tunable through the choice of the inspecting wavelength and the corresponding periodicity of the photonic structural material. In addition, there is a need for systems and methods for detecting perturbations that have a multi-dimensional level of sensitivity.
It is with respect to these and other considerations that the disclosure made herein is presented.